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Influence of aging and calorie restriction on MAPKs activity in rat kidney
Hyon Jeen Kim1, Kyung Jin Jung, Byung Pal Yu
1Department of Pharmacy, College of Pharmacy, Pusan National University, Gumjung-ku, Pusan 609-735, South Korea.
Abstract:
Mitogen-activated protein kinases (MAPK), which include the extracellular signal-related kinases (ERK), the c-Jun N-terminal kinases (JNK), and the p38 MAPK, are important regulatory proteins by which a wide variety of extracellular signals are transduced into intracellular sites. Recent studies reported that mitogenic signal transduction in various cell types are exquisitely sensitive to reactive oxygen species (ROS) and the celluar redox status. In the present study, we investigated the activation of MAPK activity by aging and calorie restriction (CR) in rat kidneys isolated from Fischer 344 rats, ages 6, 12, 18, and 24 months fed ad libitum (AL) and CR diets. Results showed that the aging process strongly enhanced all three of the MAPK activities studied, ERK, JNK, and p38 MAPK, in parallel to increased ROS status. In contrast, we observed CR to markedly suppress the age-related activation of MAPKs. Based on these data, we concluded that an age-related increase in MAPK activity is associated with increased ROS, which was effectively suppressed by the anti-oxidative action of CR.
Insights
Aging increases mitogen-activated protein kinase (MAPK) activity and reactive oxygen species (ROS) in rat kidneys. Calorie restriction (CR) suppresses this age-related MAPK activation, suggesting an antioxidant effect.
Area of Science:
- Cellular Biology
- Aging Research
- Biochemistry
Background:
- Mitogen-activated protein kinases (MAPKs) are crucial for signal transduction.
- Cellular redox status and reactive oxygen species (ROS) influence MAPK signaling.
- Aging is associated with altered cellular signaling and oxidative stress.
Purpose of the Study:
- To investigate the impact of aging and calorie restriction (CR) on MAPK activation in rat kidneys.
- To explore the relationship between MAPK activity, ROS levels, and aging.
- To determine if CR can mitigate age-related changes in MAPK signaling.
Main Methods:
- Kidneys were isolated from Fischer 344 rats of varying ages (6, 12, 18, 24 months).
- Rats were fed either ad libitum (AL) or a calorie-restricted (CR) diet.
- Activity levels of ERK, JNK, and p38 MAPK were measured.
- ROS status was assessed in relation to MAPK activity.
Main Results:
- Aging significantly increased the activity of ERK, JNK, and p38 MAPK in rat kidneys.
- Increased MAPK activity correlated with elevated ROS levels during aging.
- Calorie restriction (CR) markedly suppressed the age-related activation of all three MAPKs.
Conclusions:
- Age-related increases in MAPK activity are linked to heightened ROS levels.
- Calorie restriction (CR) effectively counteracts age-associated MAPK activation.
- CR's antioxidant actions may play a key role in modulating MAPK signaling during aging.